On June 13, 2003, at 0940 mountain daylight time, a Cessna T210N, N210MP, piloted by a private pilot, was substantially damaged during an in-flight fire near Tribune, Kansas. The pilot diverted to and landed at Tribune Municipal Airport (5K2), Tribune, Kansas. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 91 personal flight was not operating on a flight plan. The pilot and three passengers were uninjured. The flight originated from Stevens Field (2V1), Pegosa Springs, Colorado, at 0700 and was en route to Osborne Municipal Airport (K75), Osborne, Kansas. According to the Federal Aviation Administration (FAA), the pilot reported there was an uncommanded extension of the nose wheel landing gear during cruise flight. The pilot diverted to 5K2 for landing but did not notice any evidence of smoke or fire until a postflight inspection of the airplane. The cowling around the engine's turbocharger was consumed by fire and the firewall exhibited fire damage. Examination of the airplane by a Federal Aviation Administration (FAA) maintenance inspector revealed that the turbocharger exhaust tailpipe clamp had a multi-segment steel self locking nut. A single piece steel self locking nut is required for the application. A National Transportation Safety Board Pilot/Operator Aircraft Accident Report form was not received from the pilot.